Bellows sealed butterfly valve

ABSTRACT

The specification and drawings disclose a valve particularly suited for use in critical vacuum systems. The valve shown comprises a body having a through flow passage of generally circular cross-section. A butterfly valve disc is positioned in the passage and has an outer periphery adapted to close the passage when rotated to a position transverse to the axis of the passage. A rotatable operating stem is connected to the valve disc and extends outwardly through the body. Joined with the operating stem is an actuating stem which has an outer end portion inclined at an angle relative to the axis of the operating stem. A bellows assembly encloses the actuating stem with a lower portion of the assembly joined to the body. The bellows assembly includes a flexible, gas impervious bellows member which encloses the actuating stem and is inclined throughout a portion of its length at an angle corresponding to the angle of the inclination of the outer end portion of the actuating stem. Additionally, the outer end of the bellows is rotatably engaged with the outer end of the actuating stem. Means are provided in the form of a rotatable housing member for applying a generally radially acting force to the outer end of the bellows assembly to produce rotation of the operating stem and deflection of the bellows without torsional loading of the bellows.

United States Patent 1 1 3, 82,685 Gallagher et al. Jan. 1, 1974 BELLOWSSEALED BUTTERFLY VALVE [75] Inventors: Bernard J. Gallagher; Earl D.[57] ABSTRACT Shufflebarger, both of Mentor; h David Simko, ParmaHeights; T e speclfication and drawmgs disclose a valve partic- RichardJ. M e dvick Brooklyn ularly suited for use in critical vacuum systems.The Heights, John Baylan Cleveland valve shown comprises a body having athrough flow g Oliver L. Danko passage of generally circularcross-section. A butterfly chesterland an of Ohio valve disc ispositioned in the passage and has an outer periphery adapted to closethe passage when rotated [73] Assignee: Nupro Company, Clev land, hi toa position transverse to the axis of the passage. A rotatable operatingstem is connected to the valve disc [22] Filed July 1972 and extendsoutwardly through the body. Joined with [2]] Appl. No.: 272,561 theoperating stem is an actuating stem which has an outer end portioninclined at an angle relative to the 52 US. Cl 251/306, 251/335 B,74/l8.1 axis ef the epetethtg Stem; A hehewe assembly 511 Int. Cl. Fl6k1/22 closes the eetttathg eteth Wtth h ltwet Potttoh Of t [58] Field ofSearch 251/306, 335; assembly jethed to the The hehtwe assembly 74/178,18 181 cludes a flexible, gas impervious bellows member which enclosesthe actuating stem and is inclined [56] References Cited throughout aportion of its length at an angle corresponding to the angle of theinclination of the outer UNITED STATES PATENTS end portion of theactuating stem. Additionally, the l,44l,794 Germain outer end of thebellows is rotatably engaged the $514968 H1924 Huh 25t/335 B X outer endof the actuating stem. Means are provided -,oo7,233 8/1952 Bosch 74/18.lin the form of a rotatable housing member for apply 3,051,008 8/1962Hamren 74/18.] 3,1 1 1,300 1 1 1963 Boone 251/306 mg a generally tadanyactmg force to t outer end of 324L467 3/1966 Young v v I 74/15 X thebellows assembly to produce rotat1on of the oper- 3,491,7s9 1/1970Callahan et al. 251 335 R x ating Stem and deflection 0f the bellowsWithout sional loading of the bellows.

Primary Examiner-Henry T. Klinksiek Attorney-Albert P. Sharpe, Ill 10Claims 5 Drawing Figures PATENTEUJAH m4 SHEET 1 OF 2 FIGZ ' FIG.

BELLOWS SEALED BUTTERFLY VALVE The subject invention is directed towardthe valve art and, more particularly, to an improved butterfly valve.

The invention is especially suited for use as a high vacuum valve andwill be described with particular reference thereto; however, as willbecome apparent, the invention could be used for many different types ofservice.

Generally, in systems where it is desired to achieve vacuums below Torr,it is not practical to use valves having rubber or the like sealsbetween the system and the atmosphere. The reason for this is that thereis a permeability problem which results in the migration of molecules ofunknown impurities through the rubber seals and subsequent introductionof them into the vacuum system. As a consequence, the use of staticallysealed valves is preferred. Statically sealed valves are, of course,already known in connection with high vacuum service. Customarily, thestatically sealed valves are of the reciprocal stern type sealed with abellows or diaphragm. Although reciprocal valves are generallysatisfactory, they do have certain disadvantages in that they are notparticularly quick acting and they have low conductance.

Butterfly valves are theoretically ideal for vacuum systems because theyare quick acting, have high conductance, and are generally more compactand more simply constructed than reciprocal valves. The main difficultywith using butterfly valves in vacuum systems has been that none areavailable which are statically sealed. The primary reason for this isthat bellows and diaphragms which can be used in statically sealedsystems are not usable in torsion. That is, it is not generally possibleto satisfactorily transmit a rotating force through a bellows ordiaphragm as is required to shift a butterfly valve. As a consequence,butterfly valves generally require the use of rubber or plastic stemseals which suffer from the disadvantage of molecular migration into thevacuum system.

The subject invention overcomes the above problems and provides abutterfly valve which is statically sealed and does not require any typeof rotary seal, resilient gaskets or the like. All joints in theoperating assembly can be metal-to-metal seals, bonded or welded, ifdesired. Further, the assembly is arranged so that when used in a vacuumsystem, there is little chance of, virtual leaks because the operatingportion of the assembly is designed for easy pump-down.

Specifically, and in accordance with the invention, the valve providedcontemplates a body having a through flow passage of generally circularcrosssection. A valve disc member is positioned in the passage and hasan outer periphery adapted to close the passage when rotated to aposition transverse to the axis of the passage. A rotatable operatingstem is connected to the valve disc and extends outwardly through thebody. Formed integrally with the operating stem or positively connectedthereto is an actuating stem which has an outer end portion inclined atan angle relative to the axis of the operating stem. A bellows assemblyencloses the actuating stem with a lower portion of the assembly joinedto the body such as by being clamped or welded thereto. The bellowsassembly includes a flexible, gas impervious bellows member whichencloses the actuating stem and is inclined throughout a portion of itslength at an angle corresponding to the angle of the inclination of theouter end portion of the actuating stern. Additionally, the outer end ofthe be]- lows is rotatably engaged with the outer end of the actuatingstem. Means are provided in the form of a rotatable housing member forapplying a force generally radially acting to the outer end of thebellows assembly and generally tangentially acting to the effectivemoment arm created by the actuating stem so that rotation of theoperating stem is produced without torsional loading of the bellows.Because of this arrangement, there are no rotating seals between theactuating assembly and the body of the valve. Moreover, the entire innerportion or interior of the bellows assembly can be open to the flowpassageway through the valve body so as to facilitate pump-down when thevalve is used in a critical vacuum system.

Another aspect of the invention contemplates that the valve disc andoperating stems are somewhat freely floating in the body so that thedisc has a self-centering action. Preferably, the actuating andoperating stems are guided by bearing means located at least two spacedpoints but arranged so as to permit some axial movement of the stems.

Accordingly, a primary object of the invention is the provision of abellows sealed butterfly valve in which there are no rotary orreciprocal stem seals.

Yet another object is the provision of a butterfly valve particularlysuited for critical vacuum systems and arranged so that virtual leaksare minimal, pump down is efficient, and all seals between the vacuumsystem and atmosphere can be metal-to-metal or bonded.

A still further object of the invention is the provision of a valve ofthe general type described which is relatively simple to manufacture andhighly reliable in operation.

The above and other objects and advantages will become apparent from thefollowing description when read in conjunction with the accompanyingdrawings wherein:

FIG. 1 is an elevational view showing a preferred embodiment of a valveformed in accordance with the invention;

FIG. 2 is an enlarged cross-sectional view taken on line 2-2 of FIG. 1and showing the valve in a closed position;

FIG. 3 is a cross-sectional view taken on line 33 of FIG. 2;

FIG. 4 is an enlarged view of bearing means of FIG. 2; and,

FIG. 5 is a view taken on line 5-5 of FIG. 2.

Referring more particularly to FIGS. 1 and 2 of the drawings, the valveis shown as including a body 10 and an actuating assembly 12 which isconnected to the body and extends outwardly therefrom. In the subjectembodiment, the body 10 is formed as one piece of cylindricalcross-section and provided with an axially extending through passage 14.Passage 14 includes a first cylindrical section 16, a tapered, seatdefining section 18 and a cylindrical section 20. It will be noted thata spaced series of bolt holes 22 are provided for connecting the body tostandard vacuum flanges. Further, gasket recesses 24 are formed aboutthe outer ends of the passageway to receive a standard soft metal gasketof the type typically used in high vacuum systems. Although not shown,the recesses 24 are normally provided with some type of gasket engagingprotuberances. It should be appreciated that other types of connectingarrangements could equally well be provided, depending upon systemrequirements, etc.

Positioned within the through passage 14 is a circular valve disc 26formed from any suitable material and having a peripherally extendingseal 28 carried thereon. The seal can be formed from many materialsdepending upon the system requirements; however, some of the newfluorocarbon compounds are particularly satisfactory. The disc itselfis, in the preferred embodiment, formed from stainless steel and isconnected to an operating stem 30 by a pair of screws 32. Screws 32extend through openings formed in the stem 30 into tapped openings inthe disc 26. The screws 32 are preferably slotted throughout theirlength to provide an air passage along the threads to facilitatepump-down and help prevent virtual leaks in the valve. (A virtual leakresults from gas being trapped in a small cavity or the like and slowlyleaking therefrom during use of the valve in a high vacuum environment.)

As shown, the stem 30 is preferably provided with a flat 34 whichengages the face of the valve disc and holds it positioned.

The lower end of stem 30 is relatively loosely received within a bore 36formed in the valve body. It should be noted that the length of thelower end portion of stem 30 is less than the total depth of the bore36. This permits some vertical freedom so that the disc and stemassembly can be somewhat self-centering. Further, a flat 38 is formedlongitudinally along the lower end of the stem to provide an airpassage.

The upper end of the operating stem 30 passes through an opening 40which connects with an enlarged counterbore 42. Adjacent the opening 40,a slot 44 is formed through the body so as to provide free communicationwith the counterbore 42.

The upper end of stem 30 is directly connected with the actuating stem,48. In the embodiment under consideration, the operating stem 30 and theactuating stem 48 are formed integrally from a single piece of stock;however, these can obviously be formed as separate elements andpositively interconnected, if desired. The details and arrangement ofthe operating stem 48 will subsequently be described.

A bonnet member 50 with a centerbore 52 of a diameter substantiallyequal to the diameter of the counterbore 42 is joined to the valve body.In the subject embodiment, the bonnet member 50 has an axially extendingsleeve portion 54 which mates with a recess 56 formed about the outerend of counterbore 42. Preferably, the sleeve is welded to the bodyabout the joint 58 as shown in FIG. 2.

The operating stem 30 and the actuating stem 48 are guided in the bonnetmember 50 by a bearing means 60. Many different types of bearings couldbe used, for example, simple sleeve bearings or the like; however, inthe subject embodiment, a ball bearing assembly is shown. In particular,as seen in FIG. 3, bearing means 60 comprises a cylindrical sleeve 62having a plurality of openings 64 formed therethrough. Balls 66 arereceived in'the openings and are sized so as to engage the inner wall ofthe bore 52 and the outer surface of the actuating stem 48. As bestshown in FIG. 2, at the juncture between the actuating stem 48 and theoperating stem 30, there is a radially extending flange 68 having afillet 70. The lower balls in the assembly rest on the flange 68 forsupport in the bore 52. This particular bearing assembly is excellentlysuited for the specific application. It creates few, if any, virtualleaks, it leaves wide-open paths for pump-down, and it properly supportsthe stems so they can transform a linear force into rotaty motion withlittle wear or frictional loss without the use of lubricants which wouldbe undesirable in a high-vacuum system.

Of particular importance to the invention is the arrangement of theactuating assembly 12 whereby the operating and actuating stems can begiven a rotary motion without the need for a rotary seal. Referring inparticular to FIG. 2, it will be seen that the actuating stem 48 has itsouter end portion bent at an incline relative to the axis of rotation ofstem 30. In the subject embodiment, the incline is shown as in the rangeof approximately 10 to 20; however, this could obviously vary.

Enclosing the actuating stem 48 is a bellows assembly 71 which includesa gas impervious, flexible metal bellows member 72. The bellows member72 has an open lower end which is connected to the bonnet member 50. Theconnection between the lower end of the bellows member 72 and the bonnetmember 50 is best shown in FIG. 4. It will be noted that a relativelyrigid annular flange member 74 is joined about the lower edge of bellows72 and extends radially outwardly therefrom. Preferably, the flangemember 74 is fusion bonded to the bellows as shown at 76. The member 74extends outwardly over a small recess 78 formed about the top surface ofthe bonnet member 50. It will be seen that a small, upwardly extendingflange 80 is positioned about the top of bonnet member 50 and acts as apositioning flange or shoulder for a metal O-ring 82 and for flangemember 74. Metal O-ring 82 serves as a seal between the bonnet member 50and the flange 74. Referring again to FIG. 2, it will be seen that aclamp or bonnet nut member 84 is threadedly connected to the bonnetmember 50 and has an inwardly extending shoulder 86 which, as shown inFIG. 4, engages the top surface of the flange 74. By tightening thebonnet nut 84, substantial sealing pressure is applied to form a tightmetal-to-metal seal between the metal O-ring, the top of the bonnetmember 50 and the under surface of flange 74. In certain instances, themetal O-ring could be eliminated and a tight metal-to-metal seal madebetween the flange 74 and the top of the bonnet member 50. Flange member74 also could be fusion bonded to bonnet member 50.

As previously mentioned, the upper end portion of bellows member 72 isinclined at an angle corresponding to the angle of inclination of theouter end of actuating stem 48. As shown, the end of bellows 72 isclosed by a generally cup-shaped cap member 87 which has a laterallyextending flange 88 welded or otherwise positively and sealingly joinedto the upper edge of bellows 72. The outer free end of the actuatingstem 48 is rotatably received and guided within the rigid cap member 87.A bore 89 is formed inwardly of cap member 87 and receives the free endof actuating stem 48.

The cap member 87 is rotatably received in a bore 90 which is formed ata corresponding angle in a member 92. Member 92 is rotatably received inthe upper end of member 84. As shown, a reduced diameter end portion ofmember 92 extends outwardly through a sleeve bearing 94 carried inmember 84.

With the arrangement thus far described, rotation of member 92 applies alateral force to the cap member 87 and will produce rotation of the stemand consequent rotation of the valve disc 26. Because of the rotatingconnection between the actuating stem 48 and the cap member 87, therotation of the stem takes place with only lateral deflection of thebellows. That is, the bellows does not rotate or undergo any torsionalloading. Thus, all connections between the bellows and the valve bodycan be positive, nonrotating connections. Consequently, the valve isparticularly suited for critical vacuum uses where rotary seals are notsatisfactory.

Although the assembly thus far described could be used withoutadditional structure, it is preferable to provide a cup shaped handlemember 100 that is connected to the reduced diameter portion of member92. As shown, handle member 100 is releasably connected by a set screw102. Although the embodiment shown is intended for manual operation, itcould obviously be used with various types of power actuators, air,electric or the like.

In order to provide positive stops for the movement of the disc, a stopmember 110 extends downwardly from handle 100 (See FIGS. 2 and 5). Aring member 106 is connected to bonnet nut member 84 and has a groove108. The groove 108 has a circumferential extent of approximately 90degrees and receives the end of the stop member 110. As shown in FIG. 5,this limits the extent of movement of the valve disc to a first closedposition (shown solid) and a second open position.

The invention has been described in great detail sufficient to enableone of ordinary skill in the valve art to make and use the same.Obviously, modifications and alterations of the preferred embodimentwill occur to others upon a reading and understanding of thespecification and it is our intention to include all such modificationsand alterations as part of our invention insofar as they come within thescope of the appended claims.

What is claimed is:

l. A valve comprising:

a body having a through flow passage of generally circular cross-sectionand a longitudinal axis;

a valve disc member positioned in said passage and having an outerperiphery adapted to close said passage when rotated to a positiongenerally transverse to the axis;

a rotatable operating stem connected to said valve disc and extendingoutwardly through said body;

an actuating stem positively connected to said operating stem and havingan outer end portion inclined relative to the axis of rotation of saidoperating stern;

a bellows assembly enclosing said actuating stem and having a lower endportion joined to said body and an outer end portion inclined at anangle generally corresponding to the angle of said actuating stern androtatably engaged therewith; and,

means for applying a generally radially acting force to the outer end ofsaid stem whereby rotation of said stem produces deflection of saidbellows substantially without torsional loading of said bellows.

2. The valve as defined in claim 1 wherein said operating stem and saidactuating stem are integrally formed. I

3. The valve as defined in claim 1 wherein the outer end of said bellowsassembly comprises a rigid cap member having an opening which receivesthe inclined end portion of said operating stem.

4. The valve as defined in claim 1 wherein said bellows assembly isenclosed by a rigid, cup-shaped housing rotatably joined to said bodyfor rotation about the axis of said operating stem.

5. The valve as defined in claim 1 wherein said operating stem issupported from said valve disc and loosely guided in aligned openings insaid body.

6. The valve as defined in claim 1 wherein said operating stem and saidactuating stem are rotatably guided at least two points by bearingmeans.

7. The valve as defined in claim 3 wherein said means for applying aradial force to said stem includes a rigid, cup-shaped housing rotatablyjoined to said body for rotation about the axis of said operating stem,and wherein said cap member is rotatably received in said housing.

8. A valve as defined in claim 7 wherein said cap member and saidcup-shaped housing are rotatably engaged through a bearing means.

9. A valve as defined in claim 1 wherein said bellows assembly includesa hollow, generally cylindrical bellows member having an open lower endpositioned about said operating stem with said lower end sealinglyclamped to said body.

10. A valve as defined in claim 9 including a clamp ring member having aflange which overlies a flange on the lower end ofsaid bellows member.

1. A valve comprising: a body having a through flow passage of generallycircular cross-section and a longitudinal axis; a valve disc memberpositioned in said passage and having an outer periphery adapted toclose said passage when rotated to a position generally transverse tothe axis; a rotatable operating stem connected to said valve disc andextending outwardly through said body; an actuating stem positivelyconnected to said operating stem and having an outer end portioninclined relative to the axis of rotation of said operating stem; abellows assembly enclosing said actuating stem and having a lower endportion joined to said body and an outer end portion inclined at anangle generally corresponding to the angle of said actuating stem androtatably engaged therewith; and, means for applying a generallyradially acting force to the outer end of said stem whereby rotation ofsaid stem produces deflection of said bellows substantially withouttorsional loading of said bellows.
 2. The valve as defined in claim 1wherein said operating stem and said actuating stem are integrallyformed.
 3. The valve as defined in claim 1 wherein the outer end of saidbellows assembly comprises a rigid cap member having an opening whichreceives the inclined end portion of said operating stem.
 4. The valveas defined in claim 1 wherein said bellows assembly is enclosed by arigid, cup-shaped housing rotatably joined to said body for rotationabout the axis of said operating stem.
 5. The valve as defined in claim1 wherein said operating stem is supported from said valve disc andloosely guided in aligned openings in said body.
 6. The valve as definedin claim 1 wherein said operating stem and said actuating stem arerotatably guided at least two points by bearing means.
 7. The valve asdefined in claim 3 wherein said means for applying a radial force tosaid stem includes a rigid, cup-shaped housing rotatably joined to saidbody for rotation about the axis of said operating stem, and whereinsaid cap member is rotatably received in said housing.
 8. A valve asdefined in claim 7 wherein said cap member and said cup-shapEd housingare rotatably engaged through a bearing means.
 9. A valve as defined inclaim 1 wherein said bellows assembly includes a hollow, generallycylindrical bellows member having an open lower end positioned aboutsaid operating stem with said lower end sealingly clamped to said body.10. A valve as defined in claim 9 including a clamp ring member having aflange which overlies a flange on the lower end of said bellows member.